Crystalline copolymers of an alpha-olefin and aromatic alkenyl thioether



United States PatentO ,410 9 Claims. (01. zen-79.7

The present invention relates to new and useful copolymers of an u-olefin and an unsaturated thioether.

It is, known that it is possible to convert a-olefins with organometallic mixed catalysts, which have become known in industry as Ziegler catalysts, at low pressure and low temperatures into high molecular weight polymers and copolymers.

According to the invention it has been found that crystalline copolymers with valuable properties can be prepared by copolymerizing by the known low-pressure proc- -ess a-olefins of the general formula CH CH-R, where in which n is a numeral from 0 to 12, preferably from 1 to 12, and Ar represents an aromatic radical. The aromatic radical can be unsubstituted or substituted singly or multiply by an alkyl, cycloalkyl, aryl, alkoxy, aryloxy, halogen, or dialkylamino group.

This finding is surprising, since it had been established that corresponding a-alkylene thioethers, e.g., alkylvinyl thioether, alkylallyl thioether, and the like, cannot be copolymerized with a-olefins but strongly inhibit a-olefin polymerization and even stop the polymerization completely, i.e., they damage or destroy, the organometallic catalyst system.

a-Olefins of the general formula CHFCHR, where R represents hydrogen or an alkyl, aryl, or alkaryl radical of 2 to 15 carbon atoms, are suitable for copolymerization with the above-mentioned thioethers. Examples of such olefins are ethylene, propylene, butene-l, 3-methylbutene-l, pentene-l, 4-phenylpentene-l, 4-phenylburtene-1, S-phenylpentene-l, heXene-l, and styrene.

Preferred thioethers with which the a-olefins can be copolymerized are ,8-naphthylbutene(3)yl thioether, ,3- naphthylpentene(4)yl thioether, fl-naphthylundeceneUO) yl thioether, phenylbutene(3)yl thioether, phenylpentene- (4)yl thioether, phenylundecene()yl thioether, p-dimethylaminophenylpentenyl thioether, p-methylphenylundecene(l0)yl thioether, p-chlorophenylbute-ne(3)yl thioether, and 3-(4-diphenyl sulfide)-propene-l. The copolymers can, of course, comprise more than one a-olefin and more than one thioether as desired.

The copolymers prepared according to the invention have a definite crystal melting point and contain 99 to 70%, preferably 99 to 85%, by weight of a-olefin and correspondingly l to 30%, preferably 1 to by weight of the unsaturated thioether. They distinguish themselves by a very high resistance to thermal and oxidative degradation and can be dyed with dispersion dyes more readily than the homopolymer of the a-olefin. The copolymers have melting points, densities, and other physical properties very similar to those o e homopolymers of the olefin, and are useful in the same applications as the homo- 3,308,104 Patented Mar. 7, 1967 ICC molecular weight stabilizers. In fact, the copolymers can serve as stabilizers for the homopolyolefins. Compared with polypropylene stabilized with low molecular weight compounds, the new copolymers have the advantage of not suffering from migration or extraction of stabilizers.

The catalysts suitable according to the process of the invention for the preparation of copolymers are the same as already known for the low-pressure polymerization of a-olefins, i.e., organometallic mixed catalysts. Combina tions of titanium trichloride with Al(C H or Al (C H Cl are particularly advantageous. A suitable catalyst system is prepared by mixing 0.1 to 20 parts,

preferably 2 to 4 parts, by weight of the organoaluminum compound with one part of titanium chloride in an inert liquid diluent, e.g., an aliphatic hydrocarbon. It is possible to use titanium chloride which has been obtained from TiCl by reduction with hydrogen or with aluminum or with an organoaluminum compound.

The copolymerization of the a-olefin and unsaturated thioether can be carried out via known techniques as a block copolymerization or as an ordinary random copolymerization, preferably in an inert liquid diluent, by adding the monomer once or several times, separately one after another or together to a dispersion of the catalyst components in an aliphatic, alicyclic or aromatic hydrocarbon, e.g., n-heptane, n-hexane, cyclohexane, cyclopentane, toluene, chl-orobenzene, anisol, or well-purified mineral oil fractions, and the like. However, the polymerization can also be carried out in the mixtures of the monomers themselves Without any diluent.

The polymerization is desirably carried out at temperatures between 30 and 150 C., preferably at 40 to C.

One can polymerize at normal atmospheric pressure or a slightly elevated pressure, preferably at about 1 to 10 atmospheres. The duration of the polymerization is desirably about 0.5 to 15 hours, preferably 2 to 8 hours. The polymerization can be interrupted by addition of an alcohol, e.g., isopropanol or n-butanol, or of a ketone, e.g. acetone. After washing with water, the powdery polymer is filtered off, washed several times with benzene, methanol, and acetone and finally dried. Alternatively, the diluent can be removed in known manner by steam distillation instead of by washing.

The copolymers obtained according to the process of the invention can be processed into molded articles by the methods commonly used for olefin polymers.

The following examples will illustrate the present invention without, however, limiting it. I

EXAMPLE 1 (a) Preparation of TiCl catalyst component Ethylaluminum sesquichloride (400 mmoles) and 200 mmoles of triethylaluminum are dissolved in 300 ml. of a parafiinic petroleum fraction having a boiling range 180- 200" C. which had been sparged with purer nitrogen and freed from water, oxygen, sulfur, and olefins. At 0 C.,

. 109.6 ml. (1000 mmoles) of titanium tetrachloride is added dropwise in-30 minutes. The deep red dispersion obtained is stirred at 0 C. for 3 additional hours and subsequently, with further stirring, tempered at C. for 5 hours. The TiCl -containing precipitate formed is diluted with 300 ml. of the same petroleum fraction.

(11) Copolymerization of phenylpentene(4)yl thioether withpropylene Triethylaluminum (l5 mmoles) and 20 mmoles of TiCl in the form of the catalyst. component described under 1(a) are added under nitrogen into 2 l. of a pe- 3 troleum fraction having a boiling range of 180200 C. and the whole is heated with stirring to 50 C. Then 50 mmoles of phenylpentenyl thioether is added to the dispersion and thereafter propylene is introduced into the 4 naphthalene at 135 C.) is obtained. Twenty (20) g. of amorphous and oily polymer is isolated by distilling oil the mother liquor. The space-time yield is 15.6 g./l. hr., 87.2% of the polymer being crystalline.

dispersion at a rate about 10% higher than the rate at 5 EXAMPLE 3 which it is consumed. The quantity of propylene introl duced is measured via a rotameter and about 10% of off Dlethylahlmlhum monoehlorlde m 18 added gas is produced. The temperature of the polymerization under hl'lfogen 2 Of the abovecmehtlohed PetT9'1eum vessel is maintained at 50 C. After hours the polymfraehon heated t0 Then 20 mmqles Tlcls 111 the erization is stopped by addition of 50 ml. of n-butanol. 10 form of the ly deseflhed e 15 added, Where- The resulting polymer slurry is stirred for minutes p for 30 mlnutes p py 1s Introduced at a r at 50 C and washed fi times with 50 1 f Warm, about 10% higher than the rate at which it is consumed. oxygen-free water of 50 C. The polymer is separated Then the P py pp y is pp and nitrogen by filtration, washed three times with n-hexane, five times dueed h uhreaeted P py removed from the each with methanol and acetone, and finally dried at 70 15 Polymenzahon Vessel (about e Then 50 C. under vacuum. Seventy-one (71) g. of a crystalline fhmeles 0f P y )y thloethef 5 added n r polymer powder, P 1 1 5 c and a reduced ifi nitrogen atmosphere and maintained under nitrogen for viscosity (1 spec./c-value) of 6.82 (measured in 0.1% 1 h nitrogen pp y 15 then pp and P pylsolution of decahydronaphthalene at 135 C.) is obtained. e h Introduced f half E111 hollf- The P py 15 By distilling off the mother liquor, 12 g. of amorphous 2 asaln drlyen out y r g 50 mmoles of phenylbutene and oily polymer is isolated. The space-time yield is 8.3 Y thloethel 1S agalh f e p for hOllr 41 1 hr 55% f the polymer being crystalline nitrogen, and the polymerization then continued for an Details of the polymerization and properties of the addltl'onal 2 hours, during Whleh hme P py is copolymers are given in the 1 troduced at such a rate that about 10% escapes as waste EXAMPLE 2 25 gas. The finishing steps of the polymerization are the same as under 1(b). A crystalline polymer powder, (a) Preparation of catalyst M.P. 164 C., and reduced specific viscosity 4.87 (meas- Ethylaluminum sesquichl-oride (2.2 moles) is dissolved urfid 01% Solutloh 0f deeahydfohaphthalene) hin 1.5 l. of a paraffinic petroleum fraction, boiling range tamed an amount 0f The PF e yl ld 1 180200 C., which had been rinsed with pure nitrogen 3 6.85 g./l. hr., 87.6% thereof the crystalline modlficatlon. and freed from water, oxygen, sulfur, and olefins, and From the mother llquof g. of amorphous and lowa solution of 2 moles of titanium tetrachloride in 300 ml. mclecular: Olly Polymers are Ohtamed 3f the p3tr0ll1hfii1fti0n idsdadded drcgpwised within 3 EXAMPLE 4 ours at e eep re lspersion orme 1s stirre 2 additional hours at 0 C. and heated with further stir- Dlethylalummum monochlonde m 15 added ring for 5 hours to 1100 C After cooling to room under nitrogen to 2 l. of the above-mentioned petroleum perature the resulting TiCl -containing precipitate is alfractlon heated. to 50 Then 50 mmoles phenyl' lowed to settle and the supernatant clear solution is pentenam'wl ihloeiher and after another 10 minutes 20 siphoned ofi. The catalyst is washed about 10 times with g' ig T1013 m the form of the Catalyst qomponent stirring with the above-described petroleum fraction and 40 escn 6 under 2(a) are addad to the Solunon'. the diluent is removed each time by siphoning ofi sequently 15 l./hr. of ethylene and 10 l./hr. of nitrogen o are introduced for 5 hours. Further treatment is the same P LY F 0ffi-naphlhylundecenfllo)yl as under 1(b). Ninety-nine (99) g. of a crystalline polyth with P pyl ne mer powder, M.P. 127 0, reduced specific viscosity Diethylaluminum monochloride (40 mmoles) is added 13.72, is obtained. The space-time yield is 9.9 g./l. hr. under nitrogen to 2 l. of the above-mentioned petroleum The Polymelf has a dehslty of 0-9025 gand o ntams fraction heated to C. Then 50 mmoles of B-naphthylby gh of ph nylpentcnyl thloether. It is charundeceneumyl thioether is added to the Solution and acterized by high thermal and oxldatlve stability in comafter another 10 minutes 20 mmoles of Ticl in the form Par1snt hOmOPOIYethYIeHeof the catalyst component described under 2(a) is added. 50 EXAM Next, propylene is introduced for 5 hours at a rate about PLES 5 8 10% higher than the rate at which it is consumed. The copolymerization of propylene with other thio- Further treatment is as in Example l(b). One hunethe s is c rried out according to Example 2 and the dred and thirty-six (136) g. of a crystalline polymerpowfinishing steps according to Example 1(b). Details of der, M.P. l64.5 C., and having a reduced specific VISCOS- the polymerization and the properties of the copolymers ity of 7.31 (measured in 0.1% solution of decahydroare summarized in the table.

TABLE COPOLYMERIZATION OF UNSATURATED THIOETHERS AND PROPYLENE AT 50 C.

Crys- Percent T eof Propylene 121 32 2 g g R Crys- Ex Copiifi meri- Supply a-Alkylenearyl Thioether Mmoles Polymer, as PZrcent ether Sigh??? fiiii e zation g. of Total Orys- Viscosity of Polymer talline Polymer 1 R d E Ph 1 t lth th 50 71 2 that.-- Fifi? s z igihtaaatr er 5. 1.. 5.2 tit his 1a;

106 1e 3"... Block d Phenylbul z enyl thi0ether- 100 60.3 37, L2 4.87 0 9111 164 5 Random Insutfieient Ntakphtlglundecenyl 50 84.2 3.5 5.80 0:91.1 1625 108 GI. 6 d .d "d 51 7 7 "d8 Execs: Phenglpentenyl thioether 5O 69 37.9 %.:5 8 100 51 83- 7 3. 3 6, 54 Q 9122 1 3 5 1 The determination of the percent by weight of the alkylenearyl thioether in the copolymer was carried out with the help of IR-spectroscopy and elementary analysis. Soxhlet extractor with 0014 for 10 hours.

The products were always dissolved and reprecipitated three times from xylene and after each of these operations extracted in a The copolyrners described in the foregoing table exhibit excellent heat stability without the addition of stabilizers, which is most remarkable considering the notoriously poor heat stability of crystalline polypropylene without added stabilizers. Unstabilized polypropylene, for example, becomes brittle in less than 24 hours when exposed to circulating air at 133 C. whereas the propylene copolyrners described in the examples do not become embrittled after exposure of more than 360 hours under the same conditions.

What we claim and desire to protect by Letters.

Patent is 1. Crystalline copolymers of an ot-olefinselected from the group consisting of ethylene and propylene with an unsaturated thioether of the general formula in which rt is a number from 0 to 12 and Ar is an aromatic radical, said copolyrners having. a definite crystalline melting point and being comprised of 99 to 70%. by .weight of a-olefin and 1 to 30% .by weight of unsaturated thioether.

2. The copolymer of claim 1 in which the a-olefin is propylene.

3. The copolymer of claim 1 in which the a-olefin is ethylene.

4. The copolymer of claim 1 in which the unsaturated ether is phenylpentene(4)yl thioether.

5. The copolymer of claim 1 in which the unsaturated ether is fi-naphthylpentene(4)yl thioether.

6. The copolymer of claim 1 in which the unsaturated ether is fi-naphthylundecene(10)y1 thioether.

7. The copolymer of claim 1 in which the unsaturated ether is pheny1butene(3)'y1 thioether.

8. The copolymer of claim 1 in the form of a block copolymer.

9; 'The copolymer of claim 1 in the form of a random copolymer.

References Cited by the Examiner UNITED STATES PATENTS 2,467,234 4/1949 Sargent et a1. 26079.7 2,877,214 3/1959 Opheim et a1. 26079.7 3,070,577 12/ 1962 Stogryn et a1 26062 JOSEPH L. SCHOFER, Primary Examiner.

W. HOOVER, Assistant Examiner. 

1. CRYSTALLINE COPOLYMERS OF AN A-OLEFIN SELECTED FROM THE GROUP CONSISTING OF ETHYLENE AND PROPYLENE WITH AN UNSATURATED THIOETHER OF THE GENERAL FORMULA 